Explain the development status of lithium battery anode materials in detail

At present, the anode materials used in lithium batteries are generally carbon materials, such as graphite, soft carbon (such as coke, etc.), hard carbon, etc. The anode materials being explored include nitrides, PAS, tin-based oxides, tin-based oxides, tin alloys, and nano-anode materials. As a lithium battery negative electrode material, the following basic properties are required: lithium battery (1) The insertion redox potential of lithium ions in the negative electrode matrix is u200bu200bas low as possible, close to the potential of metal lithium, so that the battery's output voltage is high; (2) In the matrix A large amount of lithium can be reversibly inserted and deintercalated to obtain high capacity density; (3) The oxidation-reduction potential will not change significantly, and stable charging and discharging can be maintained; (4) The intercalation compound should have good conductivity And ionic conductivity, which can reduce polarization and enable high-current charging and discharging; (5) From a practical point of view, the main material should be cheap and pollution-free; carbon negative lithium batteries show better safety and cycle life. Good performance, and carbon materials are cheap and non-toxic. At present, carbon anode materials are widely used in commercial lithium batteries. In recent years, with the continuous in-depth research on carbon materials, it has been found that by surface modification and structural adjustment of graphite and various carbon materials, the specific capacity has been greatly increased from the original theoretical value of 372mAh/g to 700mAh/g~ 1000mAh/g, and at the same time greatly increase the specific energy of the lithium battery. Currently, the research and development of lithium battery anode materials include graphite, petroleum coke, carbon fiber, pyrolysis carbon, mesophase pitch-based carbon microspheres (MCMB), carbon black, glass charcoal, etc., among which graphite and petroleum coke are the most used value. Generally speaking, according to the degree of graphitization, carbon anode materials can be divided into graphite, soft carbon and hard carbon. The graphite material has good conductivity, high crystallinity, and a good layered structure. The charge and discharge capacity can reach more than 300mAh/g, and the charge and discharge efficiency is more than 90%. It can be used with the cathode material lithium borate and lithium manganate that supply lithium sources. , Lithium Nickel Oxide, etc., the battery composed of high uniform output voltage, is currently the most used negative electrode material for lithium batteries. Soft carbon materials are carbon materials that are easily graphitized, and refer to amorphous carbon that undergoes graphitization at a high temperature above 2500°C. Soft carbon has a low degree of graphitization and good compatibility with electrolyte. Common soft carbons include petroleum coke, needle coke, carbon fiber, carbon microspheres and so on. Hard carbon materials refer to carbon materials that are difficult to graphitize. They are formed by thermal analysis of high-molecular polymers. They have a large lithium capacity (500～ Statement: Some pictures and content of articles published on this site are from the Internet, if any Infringement, please contact to delete the previous article: What are the effects of increased nickel content on batteries